How specific are anti-carbohydrate immunoglobulins? What is the nature of the combining site? To answer these questions the interactions of homogeneous immunoglobulins with carbohydrate haptenic groups will be studied. Site mapping will be studied through impact affinity labeling of the same globulins. Hybrid immunoglobulins using H,L recombinants are studied to define subunit interactions in myeloma protein. The requirements for immunogenicity in antigens are studied. BIBLIOGRAPHIC REFERENCES: Glaudemans, C.P.J., Manjula, B.N., Bennett, L.G. and Bishop, C.T.: The Binding of Phosphorylcholine-containing antigens from Streptococcus pneumoniae to Myeloma Immunoglobulins M603 and H8. Immunochem. 1977, in press. Streefkerk, D.G. and Claudemans, C.P.J.: Binding Studies on Anti-fructofuranan Mouse Myeloma Immunoglobulins A47N, A4, U61 and E109. Biochem. 1977, in press.